This invention relates to an apparatus which enables the placement of one or more lead frames in a lead frame holder such that they may be easily transported and may be affixed to a microscope stage for convenient viewing.
Various means of holding and manipulating objects to be viewed under a microscope are well known to those skilled in the art and who are experienced in the laboratory use of microscopes. For example, most laboratory-grade microscopes are provided with a stage having facilities to move a slide in both the "X" and "Y" axes. Some microscope manufacturers provide one or more slide holders which permit one to store slides between periods of use. However, there is currently no device available which will easily accept lead frames and permit their storage, transportation and viewing under a microscope. As used herein, "lead frame" refers to a conventional manufacturing method whereby a semiconductor chip is affixed to a die having a plurality of electrical leads provided thereon. The dice are manufactured by stamping procedures and any number, typically 6-10, are stamped adjacent and connected to one another. The plurality of dice is called a lead frame.
Generally speaking, holding devices for objects to be viewed under a microscope are restrained vertically; that is, a downward force is applied to the article to be viewed, as with a spring-loaded clamp affixed to the microscope stage. Certain products, for example, lead frames, are highly sensitive and must not be compressed on a microscope stage as set forth above. Any abrasion, particularly to the semiconductor chip, can cause extreme and irreparable damage, resulting in the piece being discarded.
Various devices have been proposed in the prior art for restraining and locating devices. For instance, U.S. Pat. No. 4,255,077, Smith discloses a rectangular board for positioning a printed circuit board relative to an electrical component inserting machine which inserts terminals into predrilled holes in the printed circuit board. Spring-loaded locators and a pair of diagonally opposed right-angle guides accurately center the printed circuit board within acceptable tolerances. U.S. Pat. No. 2,471,103, Franks et al discloses a spring-loaded rod affixed to a pair of pins which slide within the slots of a base plate to effectively restrain a watch case for repairs. Likewise, U.S. Pat. No. 3,088,729, Marcus discloses a quick-acting vise having a pair of jaws which are movably disposed along a track in order to hold objects therebetween. A coil spring is mounted over a rod to tension one of the jaws. A device for adjusting a specimen-holding tool for accurate positioning under a microscope is disclosed in Japanese Pat. No. 57-96527. The specimen-holding tool is compressed and fixed into the appropriate position by vertically and horizontally acting springs. Lastly, a rectangular plate holder for holding multiple sets of masks is disclosed in U.S. Pat. No. 4,711,438. U.S. Pat. No. 2,333,114, Meyer discloses a vise for holding watch pieces having a movable jaw and fixed jaw interconnected by a threaded shaft.
Therefore, there exists a need for a device capable of holding lead frames for transport, storage or viewing under a microscope.